The present invention relates to compounds that inhibit the action of the p38 mitogen-activated protein kinase, a mammalian protein kinase that is involved in cell proliferation, cell response to stimuli, and cell death. In particular, this invention relates to heterocyclic compounds that are selective and potent inhibitors of the p38 mitogen-activated protein kinase. This invention also relates to pharmaceutical compositions containing such heterocyclic compounds that inhibit the p38 mitogen-activated protein kinase.
Mitogen-activated protein (xe2x80x9cMAPxe2x80x9d) kinases mediate the surface-to-nucleus signal transduction in a cell. Protein kinases that activate and phosphorylate MAP are known as mitogen-activated protein kinase kinases (xe2x80x9cMKKxe2x80x9d). One such MKK specifically phosphorylates and activates the p38 MAP kinase (xe2x80x9cp38xe2x80x9d) and is called MKK3. U.S. Pat. Nos. 5,736,381 and 5,804,427 describe human mitogen-activated kinase kinase isoforms. International Publication No. 98/00539 describes a human gene encoding an MKK3-Interacting Protein.
Xia et al., Science, 270, 1326-1331 (1995) describes the p38 signal transduction pathway as being activated by proinflammatory cytokines and environmental stress. MKK3 is described as being involved in transducing stress signals such as nerve growth factor mediated apaptosis in PC12 cells. It is believed that inhibition of p38 activity can provide relief from acute and chronic inflammation by blocking production of cytokines such as IL-1 and TNF, thereby inhibiting the production of proinflammatory cytokines such as IL-6 and IL-8. In particular, it is believed that p38 inhibitors block the synthesis of TNFxcex1 and IL-1xcex2 cytokines, thereby providing relief from inflammatory diseases such as arthritis. Accordingly, it would be desirable to provide novel compounds that are selective and potent inhibitors of the action of p38.
International Publication No. 97/22704 describes the mitogen-activated protein kinase kinase MEK6, which can stimulate phosphorylation and activation of p38 substrates. International Publication Nos. 95/31451, 99/00357 and 98/27098 describe various inhibitors of p38. Nonetheless, there remains a great need to develop inhibitors of the action of p38 for various pharmaceutical and therapeutic applications.
Compounds described by the chemical formula (I) or pharmaceutically acceptable salts thereof: 
are inhibitors of p38.